This invention relates to methods and means for low volume production of natural gas from hydrocarbon wells, and more specifically relates to methods and means for economical wellhead compression of said gas.
Domestic oil and gas supplies have been unable to satisfy domestic demand for these products in recent years. Prices offered for these products have risen dramatically. Even so, low pressure natural gas produced from wells in the range of 20,000 to 60,000 cubic feet per day is often vented to the atmosphere for lack of an economical means to compress such low volumes of low pressure gas for entry into a gas collection pipeline system. In those cases where such gas is not vented, units currently in use are often powered by natural gas produced from the well, often consuming as much as one half of the daily natural gas production of the well to compress the other half. The loss of this gas used to run the compressor, together with the cost of the compressor's purchase or rental, has often made such gas collection uneconomical.
Further, conventional natural gas powered compressors lack the capability of restarting themselves automatically. Therefore, when flow into the gas collection pipeline is temporarily interrupted and the compressor is thereby shut down, as is common for maintenance operations such as pigging the gas collection pipelines, the gas powered compressor unit remains idle. Production of natural gas is lost until the unit is manually restarted, possibly days later.
Therefore it is an object of this invention to provide methods and means for economically compressing low volumes of low pressure natural gas at the wellhead for entry into a gas collection pipeline system.
It is a further object of this invention to provide electrically operated means to compress low volume, low pressure natural gas without objectionable rise in the temperature of the gas necessitating use of expensive intercoolers or resulting in the rejection of the gas by the gas collection system.
It is a further object to this invention to provide methods and means for compressing low volume, low pressure natural gas at the wellhead which are automatically self starting when conditions are suitable for operation.